Decanting mechanism



Dec. 13, 1938. A. SIMONSEN DECANTING MECHANISM Filed May 12, 1936 5 Sheets-Sheet l ARNTZ 5 mow/flaw INvENToR Dec. 13, A S|MONSEN DECANTING MECHANISM Filed May 12, 1936 5 Sheets-Sheet 2 ARNTZ smorqsem.

INVENTOR 1938- A, SIMONSEN 2,140,059

DECANTING MECHANISM Filed May 12, 1936 5 Sheets-Sheet 5 "Lowzame" "Rms l Ne AR NTZ SIQMONSEN INV'ENTOR ATTORNEY.

Dec. 13, 1938.

A. SIMONSEN DECANT-ING MECHANISM Filed May 12, 1936 F! 5 IO 5 Sheets-Sheet 4 AAAAM ARNTZ Smousafl INVENTOR M; ATTONE Y.

Dec. 13, 1938.

A. SIMONSEN DECANTING MECHANI SM- Filed M 12, 1936 5 Sheets-Sheet 5 AR NTZ 5 MON as N D Q I I I v I; N 0R I Patented Dec. 13, 1938 UNITED STATES PATENT OFFICE 28 Claims.

My invention relates to decanting mechanism.

It has among its objects to provide an improved decanting mechanism for use in connection with sewage treatment, water purification, industrial waste treatment, metallurgical, chemical and other settling, clarification, or sedimentation operations. A further object of my invention is to provide such a mechanism having an improved decanting tube constituting an improved outlet for the tanks used in such operations, and adapted to draw off the surface water or other liquids from the top of the tank during or after treatment of the material in the tank. A further object of my invention is to provide such an improved decanting tube adapted to be adjusted vertically to draw oil the surface liquid as the level of the same drops in the tank, so that the operation of removing the liquid may be facilitated and expedited without disturbing the more provide such an improved, decanting member or tube especially adapted to use in round tanks and in connection with rotatable sludge collecting means, wherein my improved decanter may be embodied in a markedly eiiective mannerand used as desired, either as effluent or influent means and to enable new and improved results to be obtained. Still another object of my invention is to provide improved raising and lowering mechanism for such a decanter tube and operative to adjust the height of the latter in accordance with the level in the tank. Still another object of my invention is to provide improved automatic controlling mechanism for such a tube controlled by the liquid level and adapted to effect and stop the lowering movement of the tube at the proper levels, all while also enabling the tube to be operated at will independently of the automatic mechanism whenever desired to raise or lower the tube. Other objects of my invention include the pro vision of improved operating mechanism of the hydraulic type for effecting raising and lowering of the tube, and the provision of improved manual and automatic con- 5 trolling mechanism associated with this hydraulic mechanism to enable the desired adjustments of the tube to be obtained. These and other objects and advantages of my improved construction will, however, hereinafter more fully appear.

In the accompanying drawings, I have shown 5 'for purposes of illustration two embodiments which my invention may assume in practice.

In these drawings,--

Fig. 1 is a partial vertical sectional view of an installation of the round tank type including a 10 rotary sludge scraper and equipped with my improved decanting mechanism;

Fig. 2 is a sectional view on line 2-1 of Fig. 1;

Fig. 3 is a sectional view on line 33 of Fig. 1;

Fig. 4 is a diagrammatic plan view oi. the gen- 5 eral installation;

Fig. 5 is an enlarged side elevation of the hydraulic raising and lowering mechanism for my decanting tube;

Fig. 6 is an enlarged side elevation of the upper 20 end 01' the tube with the float operated controlling mechanism carried thereby;

Fig. 7 is a detail view showing the control cock for the hydraulic mechanism in diiferent positions;

Fig. 8 is a detail view of the electrically controlled lowering valve;

Fig. 9 is a vertical sectional view through the push button mechanism operated by the float shown in Fig. 6;

Fig. 10 is a wiring diagram of the equipment used in connection with the above installation;

Fig. 11 is a vertical sectional view showing a square type tank equipped with a modified form of my improvement, the decanting tube herein also being raised and lowered by a modified form of operating means;

Fig. 12 is a plan view of the tank shown in Fig. 11, the sludge conveyer mechanism being removed to facilitate illustration;

Fig. 13 is a wiring diagram showing the connections used in the installation shown in Fig. 11, and

Fig. 14 is a side elevation of a manually op- 45 improved means. all as hereinafter more fully described.

As in a usual construction, the rotary scraper has so-called squeegee blades 4 carried thereon which act on the sloping bottom 3 of the tank to deliver the sludge to a hopper 3 and pipe 3a. The scraper 2 is, as usual, further carried on a rotary axially disposed stilling well member 1, which is in turn suitably journaied as, for example, on bearings 3, on a stationary central support 9, usually connected by a cat walk Ia to the wall of the tank i. This support 3 carries a motor I 0 which also has usual operative connections (not shown) to a gear I l on the member 1, operative in such manner as, after the completion of decanting, to enable the member 1 to be rotated and thereby cause the squeegee blades 3 to scrape the sediment from the bottom and deliver it to the outlet 3.

In my improved construction, it will be noted that the rotary stilling well 1 is disposed around and spaced from an additional stationary stilling well 12 fixed to and carrying the support 9 and disposed coaxialiy with but spaced'from the adjustable tube 3. This well i2 is provided with suitable openings I3, herein disposed around the same in a plurality of superimposed series, which provide communication between the inside of the well 12 and the space between that well and the outer wall 1, while the latter is also, as usual, provided with suitable openings H. Thus, an effective double stilling well structure is provided and one which is adapted to permit flow from the tank I through the members 1 and 12 into the interior of the well 12 and tube 3, or from that tube through the members 1 and I2 into the tank I. Further, it will be noted that the well structure is such as to permit the passage of any heavy material inside either well down into the sludge receiving chamber 6, the well 1 being provided with an open bottom providing escape means adapted to rotate over the sludge outlet 6 while like escape means are also provided for permitting the escape of heavy material within the well l2.

My improved decanter tube 3, disposed coaxially of the well 12, is vertically adjustable therein in an improved manner relative to a stationary vertical pipe 15 having a suitable lateral connection 15a. As shown, this tube 3 has its lower end vertically adjustable in the vertical pipe I! which is disposed coaxially of the tank bottom 5 with its upper portion preferably disposed in I and projecting above a raised conical portion I3.

In a preferred construction, the extremity of the pipe 15 carries a suitable water seal or stufling box 11 enclosing the lower end of the tube 3, although, if desired, this seal or stuiiing box may be omitted and only a relatively close fit provided between the parts 15 and 3. Further, it will be noted that herein the tube 3 is provided on its lower end with an enlarged portion 13 adapted to engage the inner wall of the pipe 13 and cooperate with the portion of the latter which fits the tube above the portion l3 thereon, in keeping the tube in the desired vertical alignment with the pipe. As a result of this construction, it will be evident that the tube 3 may be raised and lowered, as desired, in the pipe IS, in such manner as to enable the upper end of the tube 3 to be disposed at any desired level with'respect to the liquid and solid material in the tank I, while being readily adjustable into any position by'a vertical sliding movement in the pipe 15.

Referring next to the upper end of the tube 3,

itwillbenotedthatthesameishereinprovided with an upwardly flaring mouth I. adapted to receive liquid in the tank during decanting or to discharge material into the tank. It will be further noted that this mouth I3 is herein disposed in a raising and lowering frame, generally indicated at 1", comprising bottom and top plate members 23, 2| connected by spaced vertically.

disposed members 22, in such manner as to permit free flow of liquid into or out of the mouth ll, while the plates 23, 2| may also act as baiiie members when the tube 3 is used as an influent tube. Attention is also directed to the fact that the plates 23 and 2| herein are provided with notches 23 in their peripheries receiving cooperating inwardly projecting rib portions 24 on the inner stilling well l2 and cooperating with these rib portions to prevent rotation of the tube while cooperating with the lower guiding means heretofore described in guiding the tube 3 in the vertical movement thereof within the well 12. Thus, is will be evident that by merely raising or lowering the frame comprising the members 23, 21 and 22 the height of the mouth I! may be readily adjusted as desired, with the tube 3 guided in this movement at its upper end by the frame and at its lower end by the pipe I3.

Improved operative connections are herein provided for raising or lowering the tube 3. These herein include a raising and lowering rod 23 disposed coaxlally with the frame F and suitably connected at the lower end to the upper plate, as at 23. The upper end of this rod extends into an upright cylinder 21 and is provided with a piston 23 in that cylinder. Thus, when a suitable fluid is admitted to the opposite ends of the cylinder 21, the rod 23 will be raised or lowered, as desired, to raise or lower the frame F and the decanter tube 3. As the construction of the cylinder 21 may vary widely, the same-need not be specifically described other than to state that it may beof any usual construction adapted to use with actuating fluid, and that the same herein is preferably of the hydraulic type and equipped at the upper and lower ends with usual packings for the rod 23, with the upper packing adapted to permit movement of the upper end of the rod through the same. Thus, not only may the pipe 3 be readily moved to any desired vertical position, but the exposed end of the rod 23, herein indicated at 29, provides a convenient means for determining at a glance the vertical position of the tube 3.

Operatively associated with the cylinder 21 is improved means for effecting raising and lowering of the piston 23 and, therefore, of the tube 3. Herein, these means include a liquid supply pipe 33 (Fig. 5) controlled by a suitable manually operated valve 31 and communicating through a four-way control cock, generally indicated at 32, with a pipe 33 leading to the top of the cylinder 21, a pipe 34 leading to the bottom of the cylinder, and a waste pipe 35. Referring more particularly to the cock 32 (Fig. 7), it will be noted that the same is provided with a usual control handle 33 and with a rotatable movable valve body 31 having passages 33 and 33 therein. Thus, with the valve 31 open, an operator desiring to eflect lowering of the piston 23 and tube 3 swings the operating handle 36 of the cock 32 downward from the position shown in Fig. 5 to the position shown at the left in Fig. '7, and thereby establishes flow from the pipe 33 through the valve passage 33 and into the pipe 33 to the top of the cylinder 21,

while also establishing an exhaust connection 76 34 and valve passage 33 to thewaste pipe 33.

Similarly, to effect raising of the tube 3, the

handle 33 is swung to the position at the right in Fig. ,7, herein the position shown in Fig. 5, wherein'the valve passage 33 establishes a connection in the pipe and the pipe 34 leading to the bottom of the cylinder, while the valve passage; 39 establishes an exhaust connection leading from the top or the cylinder and the pipe 33 to the waste pipe 33.

Operatively associated with the above described hydraulic operating mechanism is also improved means for enabling the speed of lowering movement of the tube 3 to be varied as desired. Herein, these means include a bill-pass 40 connected around aportion of the pipe 34 and having a manually operated controlling valve 4| disposed in this by-pass and controlling the flow therethrough. Further, it will'be noted that in this construction I provide a check valve 43 in the portion of the pipe between the opposite ends of the bypass 40, this check valve being so arranged that it will permit flow through the bypassed portion of the pipe 34 to the lower end of the cylinder 21 but prevent an opposite flow through that portion of the pipe 34. Thus, when it is desired to increase or decrease the speed of lowering movement of the tube 3, it is only necessary to adjust the valve 4|, the particular setting of this valve 4| establishing the rate of discharge from the bottom of the cylinder. Further, it will be evident that, when it is desired to vary the speed of raising movement of the tube 3, this may be eflected by varying the position of the valve 3|.

Operativ'ely associated with the above described hydraulic operating mechanism is also improved mechanism for automatically effecting successive lowering operations of the tube 3 after the cook 32 and valve 8| have been moved into their positions to permit lowering. These means are herein controlled by a float 43 carried on the frame F. As shown in Fig. 6. this float 43 is fixed to the lower end of a suitable upright rod 44, which is, in turn, suitably adjustably connected, as at 45, to a transverse rod 48 which is pivoted at 41 on an upstanding bracket 41 carried on the top of the plate 2|. Thus, the float is disposed outside and below the limits of the plate 2|, in such manner as to be responsive to variations in theliquid in the tank adjacent the mouth IQ of the tube 3, while being adjustable as hereinafter described. Herein, the rod 43 is also provided with oppositely disposed. generally upstanding arms 43 and 43, each disposed at slightly less than a right angle with respect to the rod 48. Further, these arms 43 and 49 carry transversely adjustable contact actuating members It and BI, each of which is transversely adjustable relative to a nut I" fixed on the arm, and further is provided with a head 53, so that the contact actuating member may be adjusted lengthwise, as desired, and held in any desired position of adjustment. Of these members 30, II, the actuating member 50 is adapted to engage with a waterproof push button mchanism, generally indicated at 34 (Fig. 9) to actuate a movable bridging contact 53, normally held in closed position by a coiled spring 53, in such manner as to cause the contact to disengage spaced stationary contacts 51. The actuating member I I, on the other hand, is adapted to engage a similar waterproof push button mechanism 58 to actuate a movable bridging contact 59, normally held in open positlon by a spring 33, so that this contact," will 4' I then engage spaced stationary contacts-3|.

Thus, the float 43 may ride on the liquid in the tank], with both contact actuating members I50 and 3| out of engagement with their "push buttons I4 and 33. in the tank is lowered, the float 43 will be so lowered as to cause the actuating member 5| to engage its push button 53 and thereby establish current flow between the contacts 6| and make possible the operation of improved associated control mechanism, hereinafter described, to effect lowering of the tube 3. Conversely, whenthe float 43 has been raised by the liquid in the tank, the actuating member 30 will then be caused to actuate its push buton 54 to break the circuit through the contacts 51, in such manner as to make ossible a further control to interrupt further lowering of the tube 3.

Referring next to this improved controlling mechanism, it will be noted that the above described movements of the float 43 control the flow from the bottom of the cylinder 21 to the waste pipe 33. Herein, as shown in Fig. 8, this control mechanism includes a solenoid 62 having a transverse link 83 connected to its core and pivoted at However, when the liquid level 64 on a suitable bracket 33, and a valve rod 63 pivoted at 61 to the link 33 between the ends of the latter and having a valve disc 63 on its lower end controlling the flow through a port 38 in a valve Ill which carries the bracket 85 and is connected between a portion of the by-pass 40 and a portion of the pipe 34 between the ends of the by-pass. Herein,'a coiled spring II also normally holds the solenoid core in raised position and the valve in closed posit-ion. Thus, with the cook 32 in lowering position, the valve 3| in open position, and the valve 4| closed, when the push button 33 is pushed in to establish current flow between contacts 3|, it is possible through circuit connections, hereinafter described, to energize the solenoid B2 and thereby open the valve disc 63. As a result, liquid is permitted to escape from the bottom of the cylinder and flow through the pipe 10a and valve 10 to the pipe 34 and the waste pipe 33, in such manner as to effect lowering of the tube -3 and float 43. Similarly, with the cock and valves 32 and 4| in the same positions. when the push button I54 is pushed in, current flow to the solenoid 32 is interrupted through the circuit connections mentioned, in such manner as to permit the spring H to close the valve 10 and thereby automatically interrupt further discharge from the lower end of the cylinder. Here. attention is directed to the fact that the check valve 42 is here operative, in such manner as to compel flow through the pipe 10a, while it will further be noted that a needle valve 12 is also provided in the pipe 10a between the by-pass 40 and valve 10 in order to permit suitable control of the flow through the pipe 10a to regulate the speed of lowering movement, as desired.

Referring next to the circuit connections mentioned, which are shown in Fig. 10, it will be noted that the same include a relay, generally designated by R, which is disposed between the switches operated by the push buttons 54, 58 and coil 84 of the solenoid 62 and operative to control 'the circuit connections, in such manner as to obtain the desired successive making and breaking of the circuit of coil 84 of the solenoid 62. This relay R herein comprises a plurality of spaced bridging contacts 13, 14 carried on and movable with a solenoid core 15 movable within an actuating coil 18, while both bridging contacts 13, 14

are normally held in open position by a coiled spring 11. Further, it will be noted that a switch 18 is provided to control the connection to the source or line 18, and that a shunt 88 is connected around the coil 18 to one of the contacts 81, Ma controlled by the bridging contacts 18, while the other bridging contact 18 controls contacts 82, 82a, one of which, 82a, is connected through a conductor 88 to the coil 88 of the solenoid 62, while the other is connected to a conductor 85 leading from the line to one of the contacts 51 controlled by the push button 58. The other contact 81 is connected by a conductor 85a to one of the contacts 8! controlled by the push button 58 and this conductor 88a is also connected through a conductor 88 to the contact 8 la. The other contact Si is connected through a conductor 81 with the coil 18 of the relay R and with the shunt 88, while the opposite end of the'coil 16 is connected through a conductor 88 with a conductor 88 extending between the switch 18 and the solenoid coil 88.

As a result of my improved mechanism and these improved circuit connections, it is possible to effect a wholly new decanting operation to remove any predetermined selected depth of surface liquid, and further to effect a wholly new automatic starting and stopping of lowering of the tube 3 as the level of the liquid in the tank I is lowered during decanting in such manner as to enable continuous decanting. Here, attention is particularly directed to the fact that the height of the liquid, which it is desired to maintain above the mouth IQ of the tube 8 at the end of each lowering operation, can be predetermined by suitable vertical adjustment of the float 88 relative to its rod 86 through the adjusting means 85. Further, it will be evident that the setting of the actuating members 58, 5| relative to the arms 88 and one another will determine the depth of each step in the decanting operation.

Referring next to the operation of the mechanism, and assuming that both of these adjustments have been made as desired, and that decanting is occurring with the level of the liquid substantially above the mouth i8 of the tube 8, it will be evident that, with the switch 18 closed, the position of the float will be such as to maintain both actuating members 58 and 5| out of engagement with their push buttons 58 and 58 until, as the float drops, push button 58 is operated. Then, current will flow from the line 18 through conductor 85, through normally closed contacts 51 controlled by push button 58, and conductor 85a, to contacts 6| controlled by push button 58, through conductor 81, solenoid coil 18. and conductor 88, and back to the line through 89 and 18. As a result of the energization of coil 16, the core of the relay R will be drawn in, in

such manner as to close contacts 82, 82a and 8|, 8|a. Current will then flow, from the line, through conductor 85, to contact 82, and through bridging contacts 18. to contact 82a and conductor 83 to solenoid coil 88, and through conductor 89 and switch 18. back to the line. As a result of the energization of coil 88 of the solenoid 82, the valve 18 will be opened to permit liquid to flow from the bottom of the cylinder 21 to the waste pipe 35, and accordingly the piston 28 and tube 3 will start to move downward. As the tube 8 is lowered, the float 88 will be raised and thereby automatically disengage the actuating member 5! from the push button 58 while the actuating member 58 is moved gradually over into position to actuate the push button 88. During the interval between breaking of the flow through the contacts 8| and breaking of the flow between contacts 81, it will be noted that flow is maintained through coil 18 and consequently through coil 88 of the solenoid 82, the circuit connections then being as follows: from the source 18, through switch 18, conductor 88, ,contacts 81, conductor 88, contact 8la, bridging contact 18, contact 8|, conductor 88, coil 18,conductor 88, and conductor 88, to switch 18, and back to the line. As a result liquid will continue to flow out from the bottom of cylinder 21 to the waste pipe 88. When, however, actuating member 88 engages push button 88 to interrupt flow through contacts 81, current flow through the coil 18 will be interrupted and the .bridging contacts 18 and 18 will be disengaged from their cooperating contacts 82, 82a and 8|, Na, in such manner as to open the circuit as a result of the action of spring 11. When the circuit is thus interrupted, the mouth iii of tube 8 will then be at the desired distance below the surface of the liquid, wherein it will remain until another lowering operation is required.

As a result of my improved construction, it is made possible to provide for automatic continuous decanting, with the decanting or eifluent pipe 8 progressively automatically lowered step by step as the liquid level falls in the tank Further, attention is particularly directed to the fact that no attention on the part of the operator is necessary other than to set the mechanism in position for lowering by setting the cock 82 in lowering position, opening the valve 8|, and closing the valve 8i and switch 18; the mechanism throughout the long decanting operation, which may take several hours, thereafter functioning entirely automatically. Attention is further directed to the fact that, when the liquid has been decanted to a .evel closely approaching the top of the more dense or solid material, the operator, after stop- .ping the automatic lowering of the tube 8 by throwing switch 18, may, if desired, thereafter continue the lowering by manual manipulation of the valve 8|, as previously described, to remove any remaining liquid disposed above the more dense material However, by setting the automatic control mechanism so that a minimum depth of liquid will beremoved in each automatic operation, it is possible either to require no such further manual operation to remove the remaining liquidor to minimize the need for such manual operation. After the surface liquid has been thus removed, it will, of course, be understood that the more dense or solid material is removed from the tank in the usual manner, with the scraper 2 operated to direct the same to the sludge hopper 8.

Attention is further directed to the fact that, due to the location of the tube 8 in the axis of the round tank I, it is made possible to withdraw the surface liquid simultaneously and evenly from all portions of the tank with a minimum of disturbance of the underlying more dense or solid material, and in such manner ,as, therefore, to obtain a very eflicient and economical operation of the liquid therefrom. As a result of my improved construction, it is also possible, when desired, to utilize this tube as an influent tube, thereby making unnecessary the provision of separate influent and effluent connections and materially sirnpiifying and cheapening the cost of the installation. This is a particularly valuable feature in connection with a round tank, in view of the relatively high cost of such installations and the possibility of reducing the cost thereof by making the influent pipe, which is fixed in the center of prior round tanks, serve as both the influent and effluent pipe in my improved construction. Further, when the tube 3 is usedas an influent pipe, it will be observed that all of the advantagesof the prior influent constructions are obtained as regards the heavy material being delivered and retained close to the sludge discharge, while my improved additional stationary stilling well I2 and improved bafile plates 20, 2| further act to concentrate the heavy material adjacent the sludge discharge by preventing any violent distribution of the same throughout the limits of the tank. At the same time, as a result of my improved construction and while eliminating the additional mechanism heretofore necessary to decant the surface liquid from a round tank, it is also made possible to effect the removal of the surface liquid with a markedly increased efliciency, never previously obtained in a round tank. It will also be observed that, whereas heretofore a round tank has been used primarily as a sedimentation tank, 1. e. having a stationary effluent weir around the top of the tank necessitating continuous operation of the tank, my improved construction makes it.

possible to substantially extend the field of use of round tanks. For example, where it is necessary to handle small volumes of waste for treatment, it is possible as a result of my improvements, to utilize the tank for collection purwaste, as heretofore only used in elutriation processes where only square tanks have heretofore been used. Further attention is directed to. the marked saving in installation and upkeep resulting from my axial effluent or decanting tube, as distinguished from the use of a plurality of eiilue'nt or decanting pipes disposed around a round tank, while the practical difficulties arising from the use of such pipes are also eliminated. Markedly improved results are also obtained by my structure as compared with those round tank constructions, wherein an effluent hose or pipe is merely thrown over theedge of the vtank to effect decanting, and a lift, suction pump or syphon must be connected to this pipe, as it will be noted that gravity decanting is made possible with my improved structure. I'hese and other advantages of my improved construction will, however, be clearly apparent to those skilled in the art.

Attention is next directed to Figs. 11, 12 and 13, wherein my improved structure is shown applied to a square tank, generally indicated at I00.

, In such a construction, the sludge is scraped to sludge hoppers IOI at one end of the tank by,

any usual scraper mechanism I02 and withdrawn from these hoppers by pipes I03. In this construction, my improved effluent pipe 3 is preferably disposed in the far end of the tank as, for example, in a chamber I 04, while being vertically adjustable in a pipe I05, as heretofore described, and having a mouth I9, as heretofore described, delivering into a frame F, likewise heretofore described. In this construction, the frame F and tube 3 are also vertically adjusted through a rod I06, but the latter is herein adjusted through a usual form of gate stand I'I operated by an electric motor I08 in a usual manner. Attention is also directed to Fig. 13 showing a substitute wiring diagram usable with this construction, which shows only the substituted circuit connections required in this installation where the motor is substituted for the hydraulic mechanism shown in Figs. 1 and 5; it being understood that the rest of the mechanism and connections shown in Fig. 10, will also be provided and connected to the conductors 83 and 89 of Fig. 13 in the same manner as in Fig. 10. Attention is also directed to the fact that a reversing switch I09 is utilized in this construction and connected in a usual manner to motor I08 in, order to reverse the motor as required to raise the tube 3 at the end of each decanting operation.

In the operation of this construction, it will be evident that the surface liquid will be withdrawn through the tube 3 as heretofore, and that the tube 3 will be automatically lowered, as heretofore, through the circuit connections shown in Fig. 10, the operation as regards lowering of the tube 3 being the same as heretofore, save that the motor I00is provided instead of the coil 84 and hydraulic mechanism. Here, attention is also directed to the fact that the motor I08 is a reversible single phase motor, and to the further fact that the reversing switch I09 effects the reversal of the motor and consequently permits raising of the tube 3 thereby, through reversing the action of the push buttons 54, 58.

In this construction, it will also be evident that, when desired to operate the gate stand I01 manually, this can be effected through the handwheel IIO, usually provided for such operation in motor driven gate stands. Here also, the tube 3 may be used as an influent pipe, if desired, or a separate influent pipe III may be provided, the latter where used preferablybeing located above the sludge discharge pipe I03 as illustrated. Obviously, when such a pipe III, is provided, either continuous or intermittent operation is feasible in either form of my invention.

In Fig. 14 I have shown a hand operated gate stand which may be used, if desired, instead of either the hydraulically operated mechanism of Figs. 1 to 10 or the modified motor operated gate stand form shown in Figs. 11 to 13. This construction includes a support I I6 suitably secured to the cross-walk IA and carries at its upper end a threaded wheel III which is threaded on the upper end of a rod II8 secured in any suitable manner to the top bafile 2| of the decanting tube 3. By turning the wheel I I I in reverse directions, the decanting tube may be raised or lowered as desired. This construction, while not preferred, is adapted to use in small installations which would not warrant the greater cost of either of the automatic equipments heretofore described.

While I have in this application described several forms which my invention may assume in practice, it will be understood that these forms of the same have been chosen for purposes of illustration, and that the invention may be modified and embodied in other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a decanting mechanism, a settling tank, a longitudinally adjustable decanting tube supported therein independently of the liquid in said tank for drawing off the surface liquid, and means controlled by the liquid level in said tank for lowering said tube as said level drops.

2. In a decanting apparatus, a settling tank, a longitudinally adjustable decanting tube therein, and stationary stilling well forming means surrounding said tube and in which the latter is adjustable.

3. In a decanting apparatus, a settling tank, a longitudinally adjustable decanting tube sup ported therein independently of the liquid in said tank, and stilling mechanism surrounding said tube in different positions thereof including a plurality of spaced stilling well forming members.

4. In a decanting apparatus, a settling tank, a vertically adjustable tube mounted in the bottom of said tank, and stilling mechanism surrounding said tube including spaced stilling well forming members and baffle means adjustable with. said tube.

5. In a decanting apparatus, a round settling tank, a coaxial longitudinally adjustable decanting tube therein, stilling mechanism coaxial with said tube comprising inner stationary and outer rotatable stilling well forming members, a rotary collector rotatable around said tube with said outer member, and means for rotating said outer member and collector.

6. In a decanting mechanism, a settling tank, a longitudinally adjustable decanting tube therein, mechanism for lowering said tube including an hydraulic cylinder and controlling mechanism for the latter including means for eflecting automatic lowering of said tube step by step.

7. In a decanting mechanism, a settling tank, a longitudinally adjustable decanting tube therein, mechanism for lowering said tube including an hydraulic cylinder and controlling mechanism for the latter including means for eflecting automatic lowering of said tube step by step and a float controlling said last mentioned means.

8. In a decanting mechanism, a settling tank, a longitudinally adjustable decanting tube therein, mechanism for lowering said tube, and controlling mechanism for said mechanism having means for efiecting automatic lowering of said tube step by step including a float and means controlled by said float for starting and stopping lowering by said lowering mechanism.

9. In a decanting mechanism, a settling tank, a longitudinally adjustable decanting tube therein, power operated means for lowering said tube, and controlling mechanism controlling said means and having means for automatically starting and stopping the same as the level falls in said tank.

10. In a decanting mechanism, a settling tank, a longitudinally adjustable decanting tube therein, power operated means for lowering said tube, and controlling mechanism controlling said means and including means for automatically starting and stopping the same as the level falls in said tank and means for reversely operating said lowering means to raise said tube.

11. In a decanting mechanism, a settling tank, a longitudinally adjustable decanting tube therein, electrically controlled mechanism for lowering said tube, and controlling mechanism for said lowering mechanism including a relay reversely operative to start and stop lowering, and automatically operative means for reversely operating said relay during decanting as the liquid level falls.

12. In a decanting mechanism, a settling tank, a longitudinally adjustable decanting tube therein, electrically controlled mechanism for lowering said tube, and controlling mechanism for said lowering mechanism including a relay reversely operative to start and stop lowering, a controlling float movable with said tube, and lowering and stopping switches operable by said float and controlling said relay.

13. In a decanting mechanism, a settling tank, a longitudinally adjustable decanting tube therein, electrically controlled mechanism for lowering said tube, and controlling mechanism for said lowering mechanism including a relay reversely operative to start and stop lowering, a controlling float movable with said tube, and lowering and stopping switches operable by said float, said relay having a controlling coil and a shunt around the same controlled by said switches.

14. In a decanting mechanism, a settling tank, an adjustable decanting tube therein, means for lowering the same as the liquid level falls in said tank, and controlling mechanism for said lowering means including lowering and stopping switches, a controlling relay movable into stopping and lowering position, and means for maintaining said relay in lowering position after the operation of said lowering switch until said stopping switch is operated.

15. In a decanting mechanism, a longitudinally adjustable decanting tube, means for lowering the same during decanting, and controlling mechanism for said lowering means including float means carried on said tube and switch mechanism comprising a plurality of contacts operated by said float means at the opposite limits of travel thereof.

16. In a decanting mechanism, a longitudinally adjustable decanting tube, means for lowering the same during decanting, and controlling mechanism for said lowering means including float means carried on said tube, and switch mechanism comprising a plurality of contacts operated by said float means at the opposite limits oi travel thereof, said float means comprising a switch actuating portion and a float portion adjustable relative to said actuating portion and actuating the latter.

17. In combination, a longitudinally adjustable decanting tube, fluid operated mechanism including a cylinder having a piston connected to said tube, fluid supply and exhaust connections to said cylinder for lowering said tube, and electro-responsive means for opening and closing the supply through said exhaust connection as said tube is lowered.

18. In combination, a longitudinally adjustable decanting tube, fluid operated mechanism including a cylinder having a piston connected to said tube, and fluid supply and exhaust connections to said cylinder for raising and lowering said tube including a one-way valve, a by-pass around said valve, and electro-responsive means controlling the flow through said by-pass.

19. In combination, a longitudinally adjustable decanting tube, fluid operated mechanism having a movable element connected to said tube, fluid supply and exhaust connections to said mechanism for lowering said tube, and means for intermittently opening and closing said exhaust connection during the decanting operation.

20. In a decanting mechanism, a longitudinally adjustable decanting tube, raising and lowering mechanism therefor including an electric motor, electric controlling mechanism for said motor for effecting lowering of said tube including a plurality of switches and a float automatically controlling said switches and movable with said tube, and a reversing switch controlling the direction of rotation of the said motor and reversing the action of said switches.

21. In a decanting mechanism, a settling tank having a scraper mechanism therein and a sludge outlet receiving sludge delivered by said scraper mechanism, a longitudinally adjustable decanting tube in said tank disposed out of the path of said scraper mechanism, and means for adjusting said tube into different positions during decanting.

22. In a decanting mechanism, a settling tank having a collector mechanism therein and a sludge outlet receiving sludge delivered by said collector mechanism, a longitudinally adjustable decanting tube in said tank, and means for adjusting said tube into different positions during decanting, said collector mechanism being rotatable about the tank axis and said tube being dis posed coaxially of said collector mechanism.

23. In a decantingmechanism, a settling tank having a collector mechanism therein and a sludge outlet receiving sludge delivered by said collector mechanism, said collector mechanism being rotatable about the axis of said tank, and a vertically adjustable decanting tube disposed around the axis of said collector mechanism and extending upward through the bottom of said tank.

24. In.a decanting mechanism, a settling tank having a collector mechanism therein and a sludge outlet receiving sludge delivered by said collector mechanism, said collector mechanism being rotatable about the axis of said tank, a vertically adjustable decanting tube disposed around the axis of said collector mechanism and extending upward through the bottom of said tank, and means for supporting said tube independently of the liquid in said tank.

25. In a decanting mechanism, a settling tank having a collector mechanism therein and a sludge outlet receiving sludge delivered by said collector mechanism, said collector mechanism being rotatable about -the axis of said tank, a vertically adjustable decanting tube disposed around the axis of said collector mechanism and extending upward through the bottom of said tank, means for supporting said tube independently of the liquid in said tank, and means controlled by the liquid level in said tank for effecting automatic lowering of said tube during decanting.

26. In a decanting mechanism, a settling tank having a collector mechanism therein and a sludge outlet receiving sludge delivered by said collector mechanism, said collector mechanism being rotatable about the axis of said tank, a vertically adjustable tube disposed around the axis of said collector mechanism and extending upward through the bottom of said tank, means supporting said tube independently of the liquid in said tank, and means cooperating with said tube for enabling the same to function selectively as desired as a decanting tube or an influent tube.

27. In a decanting mechanism, a settling tank having a collector mechanism therein and a sludge outlet receiving sludge delivered by said collector mechanism, said collector mechanism being rotatable about the axis of said tank, a vertically adjustable tube disposed around the axis of said collector mechanism and extending upward through the bottom of said tank, means supporting said tube independently of the liquid in said tank, stilling well forming means enclosing the upper end of said tube, power operated means for raising and lowering said tube, and selectively operable manually and float controlled means for controlling the operation of said power operated means.

28. In a decanting mechanism, a settling tank having a collector mechanism therein and. a sludge outlet, a longitudinally adjustable decanting tube in said tank, and means for adjusting said tube into different positions during decanting, said tank being of substantially rectangular shape and said collector mechanism operating longitudinally thereof and delivering to said sludge outlet, and said decanting tube being disposed outside the limits of said collector mechanism.

ARNTZ SIMONSEN. 

